Flexible ceramic substrates offer significant technological advantages over commonly used soda-lime glass substrates. For example, flexible ceramic substrates have extremely high temperature resistance (with a softening point twice that of glass), from about 40 to about 80 times lower mass and thermal budget (which translates to proportionally faster heating/cooling times and lower energy consumption) and roll-to-roll (R2R) manufacturing compatibility. These qualities can result in higher-efficiency photovoltaic devices (due to higher processing temperatures), as well as a lower-cost, less labor-intensive industrial process.
The inertness and high temperature resistivity of ceramics is particularly important for materials which require high-temperature treatments (e.g., those above 500° C.) in aggressive environments, such as chalcogen-containing atmospheres used for high-quality chalcogenide solar cell absorbers. Insulating properties of ceramics allow monolithic series interconnection of photovoltaic devices through simple patterning.
S. Ishizuka, “A flexible CIGS solar cell with energy conversion efficiency of 17.7%” AIST TODAY, Vol. 8, No. 10 p. 20 (2008) (hereinafter “Ishizuka”) describes CIGS devices on flexible substrates such as metal foils, ceramic sheets, and polymers. Ishizuka describes a CIGS solar cell with a flexible zirconia ceramic substrate having a 17.7% efficiency. Indium (a component of CIGS) is however a rare earth element, thus making the implementation of CIGS based materials expensive for wide scale production.
Thus, high-efficiency, low-cost alternatives to conventional CIGS-based devices which take advantage of the efficiency and manufacturing benefits of flexible ceramic substrates would be desirable.